Method and apparatus for corrugating sheet metal by a reciprocating bender with a pivoted side shaper



June 21, 1949.- M. N. LEBEDEFF 2,473,533

\' METHOD AND APPARATUS FOR CORRUGATING SHEET METAL BY A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER 8 Sheets-Sheet 1 Filed Dec. 19, 1946 June 21, 19 M. N. LEBEDEFF METHOD AND APPARATUS FOR CORRUGATING SHEET METAL BY A RECIPROCATING BENDER WITH A PIVQTED SIDE SHAPER 8 Sheets-Sheet 2 Filed Dec. 19, 1946 June 1949- M. N. LEBEDEFF 2,473,533

METHOD AND APPARATUS FOR CORRUGATING SHEET METAL BY A RECIPROCAT-ING BENDER WITH A PIVOTED SIDE SHAPER Filed Dec. 19, 1946 8 She'ets-Sheet 5 %Z0%Qe/ 17f 6560 6 June,2l,'1949. M. N. LEB EDEFF 1 3, METHOD AND APPARATUS FOR CQRRUGATING SHEET METAL BY A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER- Fi led D60. 19-, 1946 8 Sheets-Sheet 4 8 Sheets-Sheet 5 June 1949- r M. N. LEBEDEFF 7 METHOD AND APPARATUS FOR GORRUGATING'V SHEET METAL BY A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER Filed Dec. 19, 1946 Z F M June 1949- M. N. LEBEDEFF METHOD AND APPARATUS FOR- CORRUGATING SHEET METAL BY A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER Filed D80. 19, 1946 8 Sheets-Sheet 6 /6 MW /f% 3 1710 72307."- ./VZ'c/?Qe/6Zea awa m June 1949- M. N. LEBEDEFF 2,473,533

METHOD AND APPARATUS FOR CORRUGATING SHEET METAL BY A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER Filed Dec. 19, 1946 8 Sheets-Sheet '7 I g l l I l l W s Sheets-She et 8 M. N. LEBEDEFF METHOD AND APPARATUS FOR GORRUGATING SHEET METAL BY ,A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER June 21, 1949.

Filed Dec. 19, 1946 E m W, @W W QN N M Patented June 21, 1949 UNITED NIETHOD AND APPARATUS FOR CORRUGAT- ING SHEET METAL BY A RECIPROCATING BENDER WITH A PIVOTED SIDE SHAPER Michael N. Lebedeif, Chicago, 111., assignor to Chicago Bridge & Iron Company, a corporation of Illinois Application December 19, 1946, Serial No. 717,277

7 Claims. 1

This invention relates to a die, and more particularly to a die adapted to form a permanent corrugation in a sheet of material.

While this die is particularly adapted and designed to corrugate galvanized sheet metal in the manufacture of flexure shoes for use with floating roof tanks, (the particular type of flexure being disclosed and claimed in the pending application of Goldsby and Orr entitled Floating roof seal being Serial Number 636A42), it is adaptable to form corrugations in sheet material for other purposes.

It has been extremely difiicult in the past to form a corrugation in galvanized sheet metal without destruction of the surface, and it has, therefore, been customary to form a corrugation by various methods in a strip of untreated sheet metal and then to subject the corrugated sheet to galvanizing treatment. This has, of course, greatly increased the cost of such material and has often given rise to diificulty in the subsequent galvanizing process.

I have invented and am herein disclosing and claiming a die which is capable of forming permanent corrugations in sheet metal, galvanized or ungalvanized, Without damage to the surface.

The invention will be described as shown in the accompanying drawings in which,

Fig. l is a front elevation of the die;

Fig. 2 is a top elevation of the die, partly in section;

Fig. 3 is a side elevation;

Fig. 4 is an enlarged view of a portion of the front of the die showing a piece of sheet material in position thereon;

Fig. 5 is a view of a sheet of material in position on the die;

Fig. 6 is an end view of the sheet material before the formation of a corrugation therein;

Fig. '7 is a cross-section through the sheet material showing a corrugation therein;

Fig. 8 is a cross-section of the sheet material along line 8-8 of Fig. '7;

Fig. 9 is an enlarged detailed view of the front of the die with the strip of sheet material in position at the outset of the pressing operation;

Fig. 10 is a view like Fig. 9 at an intermediate stage of the pressing operation,

Fig. 11 is a view like Figs. 9 and 10 showing the member having flat table-like projections 2| and 22 on either side thereof on which the outer portions of the sheet material rest during the operation. A movable member 23 is connected to a hydraulic press (not shown), or other such device adapted to move the member 23 into pressing contact against the base member 20. To insure that the movable member is correctly centered over the base member, the rods 24 and 25 are provided, the rods being received into the circular openings 25 and 21 provided in the lugs 28 and 29 on the base member when the members 20 and23 are correctly aligned.

Referring more particularly to Figs. 9 to 11, the movable member 23 is provided with a pair of elongated hold-down members 3|] and 3| which are received in slots 32 and 33 provided in the movable member. The hold-down members 36 and 3| are adapted to be received into the slots 32 and 33 in response to pressure and are forced into the slots against the resistance of springs 34 and 35. The slots are provided with shoulders 35 and 31 which are adapted to engage shoulders 38 and 39 on the hold-down members to prevent those members from sliding out of the slots upon release of pressure. An elongated presser bar Ml is mounted on the movable member, the presser bar having an operative position, as shown in Fig. 9, in which it is adapted to press a channel in a strip of sheet material 6| resting upon the base member. The presser bar is fitted into a recess 42 in the movable member, which recess opens at its upper end to a larger recess i3 into which the top of the presser bar projects. Also located within the recess 43 is a bar 44 which is adapted to be positioned between the top of the presser bar and the upper surface of the recess to hold the bar in its operative position. This bar 44 is movable to one side of the recess 43 to the position shown in Fig. 11 and the presser bar so may then be lifted to a position where it is approximately flush with the lower end of the member 23. A shoulder 45 on the presser bar rests on the upper surface of the bar 44 to hold the presser bar in its inoperative position, away from the sheet material during the second cycle of the die. While in the embodiment shown, the movement of the bar 44 to the alternate positions shown in Figs 9 and 11, and the movement of the presser barllll from the operative to the inoperative position are accomplished manually, it is clear that the; presser bar may be shifted to its two positions-by mechanical or automatic means.

Mounted within thebase member 2|! are two resting in complimentary curved grooves 50 and 5| in the base member to permit the members 46 and 47 to oscillate, or partially rotate, about the axis of the arcuate portions. The lower portion of the members 46 and 41 rest upon the channeled bar 52 which bar in turn is movable within the guideway 53 formed in the base member. The bar 52 is urged in an upward direction by a plurality of springs 54, said springs having one end resting on the bottom of the guideway 53 and the other end pressing against the bottom of a channel 55 formed in the bottom of the member 52. The upper portion of the bar 52 has a channel 55 formed therein in which the elongated setting element 5! is positioned. A plurality of plungers 58 extend through holes 59 formed in the member 52. The plungers 53 are provided at their upper ends with an enlarged portion 68 slidable within a hole of larger diameter 5i at the upper end of the hole 59. This enlarged portion by its contact with the upper end of the hole 59 limits the downward movement of the plunger, and the lower end of the plunger is adapted to contact the bottom of the channel 53 at various positions predetermined by the adjustable setting of bolt 62 secured to the lower end of each plunger 53. The reason for the plungers and their adjustment will hereinafter become apparent.

The function of the various elements just described are perhaps best understood by a description of the operation of the die. With the members 2B and 23 separated in the position shown in Fig. 4, the strip of sheet material All is placed between the two members. Means are provided for centering the sheet material directly beneath the elongated presser bar, the particular centering device in the embodiment shown comprising the two arms 63 and 6d. The arms are normally urged apart by springs and 55. The tension of the springs may be overcome by manual pres sure to bring the upper portion of the arms into alignment for insertion into a slot it: formed. in the sheet material at the location of the desired corrugation. The spring means then serves to urge the arms apart holding the material by engagement with the sides of the slot. The arms are interconnected, so that each will move an equal distance from the center point, by means of the intermeshing gears 65 and 69 to which the arms are pivctally connected by members it) and l I, as shown. The above members comprising the centering means are mounted upon a plate 80 which in turn is pivotally mounted to a plate 8! attached to the base member 26, the pivoting being accomplished by a pin 82 journaled in the plates 83 and Bi, A handle 83 is provided by means of which the centering means may be pivoted to a point where the arms 63 and 54 are moved out of engagement with the slot.

With the sheet so held in its desired position beneath the member 23, the hydraulic means are brought into operation whereby the member 23 is moved towards the base member 25 until the position shown in Fig. 9 is attained. At that point, the presser bar 49 has begun to press a channel in the sheet material, and the hold-down members 58 and 35 are holding the sheet against the supporting me nbers id and ll. Continuing the operation of the die, a channel is pressed into the material to the extent shown in Fig. 10. At that point, the pressure from the hold-down members has rotated or oscillated the members 46 and 47 toward each other thereby compressing the springs 5 3, 35 and 55. The sheet material Will, of course, slide towards the center,

' depression to the shape shown in Fig. 11.

where the depression is being formed, and it is the function of the hold-down members 30 and 3| to permit such sliding or slipping of the sheet material to prevent the stretching thereof. With the parts in relationship, shown in Fig. 10, the edges of the members 46 and 4'! are spaced by two intervening thicknesses of the sheet material and the presser bar, and the channel member 52 has been pressed downward within the guideway. Withdrawing the member 23 from contact with the base member completes the first cycle of operation of the die.

In the second cycle of the die, the presser bar is moved to its inoperative position and the member 23 is again moved downwardly, the hold-down means pressing the sheet material against the supporting members 45 and ll and rotating the edges of those members toward each other. As the member 23 moves downwardly, the centering means, hereinbefore described, are pivoted by the operator by a pull upon the handle 83 which moves the arms of the centering means out of engagement with the slot and permits the complete closing of the slot in the ensuing second cycle. Inasmuch as in this cycle the presser bar is in its inoperative position, the member 46 and G! can rotate a greater distance, bringing their edges toward each other to the point where they are spaced only by two thicknesses of the sheet material. This great-er rotation of the supporting members closes the U -shaped channel in the sheet z-l and also causes the channel member 52 to be depressed a greater distance into the guideway During such greater depression, the bolts 62 on the bottom of the plungers 58 contact the bottom of the guideway and halt further downward movement of the setting element 57. The depression in the sheet material is moved downward against this setting element, bending the This efiects a bending of the material beyond its elastic limit and permanently sets the corrugation therein. Upon raising of the movable member 23, the sheet material has a corrugation formed therein, as illustrated in Figs. '7 and 8.

The presser bar extends the entire length of the die as do the hold-down members, the supporting members, the setting element and the channeled bar. To accommodate the edges of the supporting members to various widths of sheet material and to vary the siZe of the corrugation formed therein, the edges and 16 are removable and replaceable with others of various widths and lengths.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. The method for forming a permanent corrugation in a flat sheet which comprises pressing a U-shaped depression transversely of the entire sheet, and of substantially the same wall thickness as the remainder of the sheet into a portion of said sheet while slipably holding the sheet on both sides of the depression area to restrict movement thereof, removing the pressing member from within the U to leave the same free closing the upper edges of the U by lateral pressure and then imposing a force, at the bottom of the U, greater than the elastic limit of the material, substantially perpendicular to said lateral pressure while increasing said lateral pressure and then moving the sheet laterally a predetermined distance and repeating the forming steps.

.2. A corrugating machine for forming a permanent corrugation in a sheet including means for, in seriatim, slipably holding said sheet by pressure on its upper surface, said holding pressure pressing the lower surface against at least a pair of transverse spaced oscillatory pressure resistant means, means for pressing a U-shaped channel in the portion of the sheet in the space between said holding means while said holding means holds said sheet by pressure on each side of said portion, means for releasing said holding pressure, means for reapplying said holding pressure with said pressing means withdrawn from said channel, said reapplied holding pressure oscillating said pressure resistant means a greater extent whereby said space is decreased and said means exert lateral pressure on the channel to close the U and means for imposing a force greater than the elastic limit of the material substantially perpendicular to said pressure at the bottom of the U.

3. The machine of claim 2 in which said pressing means comprises an elongated presser bar, said presser bar having an operative position wherein it is adapted to press a U-shaped channel in the sheet and said bar being adapted to be moved to an inoperative position before the reapplication of said holding pressure wherein said bar remains out of contact with said sheet and means for supporting said bar comprising an upper relatively wide slot and a lower slot connected to the upper slot said lower slot having a width to receive the presser bar, a second bar in said upper slot adapted to be positioned over the presser bar when the presser bar is in operative position, said second bar being adapted to be moved laterally in said upper slot to one side of the presser bar for supporting the presser bar in inoperative position.

a. A corrugating machine for forming a permanent corrugation in a sheet comprising a base member, an elongated presser bar, a movable die member carrying the presser bar, means for moving the movable die member to press said bar against a flat sheet to form a depression therein, holding means for slipably holding said sheet, said holding means comprising a first pair of members mounted on the movable die member and spring urged against one surface of the sheet and a second pair of members oscillatorily mounted on the base member about axis substantially parallel to the presser bar and adapted to contact the other surface of said sheet and to be rotated about said axis in response to pressure from said first pair of members, said second pair of members rotating in opposite directions so as to cause their adjacent edges to approach each other, and an elongated setting element mounted on the base member between said second pair of members, said machine having a first cycle in which the presser bar is pressed against the sheet to form a depression therein and then removed from said depression and a second cycle in which said second pair of members are rotated toward each other to press their edges against the sides of said depression to close the same while said setting element contacts the bottom of said depression to bend said portion beyond the elastic limit thereof.

5. The machine of claim 4 in which said presser bar has an operating and a non-operating position and is adapted to be pressed into pressing contact with the sheet only while in the operating position, and means for supporting said bar comprising an upper relatively wide slot and a lower slot connected to the upper slot said lower slot havin a width to receive the presser bar, a second bar in said upper slot adapted to be positioned over the presser bar when the presser bar is in operative position, said second bar being adapted to be moved laterally in said upper slot to one side of the presser bar for supporting the presser bar in inoperative position.

6. The machine of claim 4 in which said second pair of members rotate a certain amount during the first cycle and rotate a greater amount during the second cycle, said greater rotation moving said depression downward into setting contact with said setting element.

7. The machine of claim 4 in which said setting element comprises a supporting member adapted to be movable downwardly in response to pressure from said second pair of members, a work engaging member carried by said supporting member and movable downwardly therewith, and a plurality of adjustable stops adapted to terminate the downward movement of said work engaging member independently of the supporting member during the second cycle whereby said material is bent beyond the elastic limit thereof.

MICHAEL N. LEBEDEFF.

REFERENCES CITED The following references are of record in the of this patent:

UNITED STATES PATENTS Number Name Date 254,249 Vanstone Feb. 28, 1882 696,358 Bailey Mar. 25, 1902 927,302 Walton July 6, 1909 948,551 Rigby Feb. 8, 1910 1,058,775 McKillop Apr. 15, 1913 1,111,403 Ohl Sept. 22, 1919 1,127,109 Tarpenning Feb. 2, 1915 1,195,538 Wadhams Aug. 22, 1916 1,225,730 Gargiulo May 8, 1917 1,771,681 Kahn July 29, 1930 2,125,427 DeGanabl Aug. 2, 1938 FOREIGN PATENTS Number Country Date 1,384 Great Britain Jan. 19, 1914 15,519 Great Britain Oct. 29, 1888 

